North of Gainesville, a church camp once attracted thousands of visitors because it was built around the gushing waters of Hornsby Springs. Then the spring stopped flowing and the camp had to spend more than $1 million to build a water park to replace it. The old spring site is now so stagnant that it's frequently declared unfit for humans to swim in. In Silver Springs, where the water was once so clear it was as if the fish swam through ­air, there are now goopy mats of algae so thick that alligators can perch atop them. And in the Ocala National Forest, the gurgle of fresh water pouring out of popular Silver Glen Spring is slowly growing saltier. Deep beneath the ground we stand on, below the strip malls and the condos and the lush green of the golf courses, runs a river of water that makes life in Florida possible. The underground aquifer rushes through Swiss cheese caverns, its hidden flow bubbling up to the surface in Florida's roughly 1,000 springs — the greatest concentration of springs on Earth.

A century ago Florida's gin-clear springs drew presidents and millionaires and tourists galore who sought to cure their ailments by bathing in the healing cascades. Now the springs tell the story of a hidden sickness, one that lies deep within the earth:

• The water in many springs no longer boils up like a fountain, the way they have for centuries. The flow has slowed. In some places it has even stopped or begun flowing backward.

• The water that does come out is polluted by nitrates.

• The pollution fuels the growth of toxic algae blooms, which are taking over springs and the rivers they feed and putting human health at risk.

• Finally, the fresh water coming out of many springs is showing signs of a growing saltiness, according to a study by the Florida Geological Survey.

All of it — particularly the saltiness — is a dark omen for the future of the state's water supply.

"It's the very same water we drink that's coming out of the springs," said Doug Stamm, author of the book Florida's Springs. "When they start to deteriorate, that's the water we drink deteriorating too."

Yet a state-sponsored effort to save the springs, launched by then-Gov. Jeb Bush 12 years ago, ended last year under Gov. Rick Scott. Groups drafting plans to restore some of the most important springs were disbanded because they lost their funding.

Faced with a backlash this year from Florida residents who cherish their springs, the state's top environmental regulator is now touting a renewed effort, even amid agency layoffs. But Bob Knight of the Florida Springs Institute in Gainesville says most of it appears to be "more in the category of pork barrel projects ... with questionable benefits to springs."

Springs once burbled up all across the state. But in South Florida they were wiped out decades ago by the ditching and draining of the landscape as well as overpumping of the aquifer. The ones that remain are in the less populated region north of Interstate 4. One former state official called them "the Everglades of North Florida."

As with the Everglades, the springs' problems begin with human alterations to their flow.

The water coming out of Florida's springs "is a blend of different ages," explained Brian Katz of the U.S. Geological Survey. "Some went in days or weeks ago," while some of it has been underground for decades.

That means that when the rain pours down, dribbling into fissures in the earth that connect to the aquifer, the springs appear to have a normal flow. It's water that just went into the ground and is now coming back out.

During the dry season, though, the older underground rivers that should keep the springs flowing year-round no longer spurt upward to become what Marjory Stoneman Douglas once called "bowls of liquid light."

Jason Polk, a geoscience professor at Western Kentucky University, has been diving in Florida's springs and sinkholes since 2004, doing research in underground caverns in Pasco, Hernando, Citrus and Marion counties. He has seen stark changes over the years.

"You go in a cave where there's no longer any water at all," he said. "Places you used to swim through, now you have to walk through. It's a permanent decline. It's just gone."

Where did it go? The evidence points to too much pumping of fresh water — millions of gallons a day sprayed on suburban lawns and farmers' fields, run through showers and flushed down toilets, turned into steam to crank turbines for electricity, or siphoned into plastic bottles for sale around the country.

Floridians use 158 gallons of water a day per person, about 50 more than the national average. Meanwhile agriculture draws more water out of the ground for irrigation than any state east of the Mississippi. As a result, between 1970 and 1995, withdrawals from the aquifer increased more than 50 percent and by 2005 hit 4.2 billion gallons a day.

As pumping grew, the flow from many springs fell. In 2006, one of the state's most powerful ones, Spring Creek Springs near Tallahassee, abruptly reversed its flow. It has never completely recovered, say local residents.

A troubling glimpse of the future comes from Hornsby Spring, northwest of Gainesville. In 1953, the Seventh Day Adventist Church bought it and built Camp Kulaqua on the 600 acres around it. The camp attracted 50,000 people a year, many of them eager to plunge into the spring's gushing depths.

Twenty years ago, "you used to could swim straight down 80 feet," recalled Theresa Sroka, a former camper who's now Kulaqua's marketing director. "There was a floating dock in the middle and the lifeguard would sit on it, because it was so deep."

But then the flow began slowing, and in 2003 it stopped.

"It became a stagnant pond," said camp director Phil Younts. The water quality fell below what the health department required for swimming, so "we had to bus kids to other places to swim."

Ultimately the camp paid $1.6 million to build a water park to replace the spring. Sometimes campers can still jump into the spring bowl, now less than 50 feet deep. Most days, though, the spring that was the centerpiece of the camp is off limits.

That hasn't happened to the biggest springs — yet. But Jeff Peterson, a cave diver who has explored many of the springs, has seen worrisome changes in Weeki Wachee Springs.

When he began exploring it in 1994, the flow was so powerful no diver could go very far. But around 2007 the pressure dropped to where exploration was so easy his team could go a mile down one tunnel.

When he hands his findings over to state water officials, he said, "They say thank you" but that's all. "They're trying to determine how much we can tolerate dragging that thing down before the ecosystem falls down."

While the Bush springs initiative was still alive, the Florida Geological Survey began pulling together its first comprehensive report on the subject in 30 years.

The report, which came out in 2009, surveyed data from 1991 to 2003. It documented the rise of pollution and the fall of flows. But the geologists didn't anticipate the most startling finding.

"The most unexpected conclusion," said Jonathan Arthur, the state's chief geologist, "was the saline indicators increasing in the springs."

This saltiness, similar to the saltwater intrusion that cost Pinellas County its original water supply wells in the 1980s, isn't just creeping in along the coast, such as in Chassahowitzka Springs and Homosassa Springs. It's also showing up far inland, including at Silver Glen Springs in Ocala National Forest.

"Saltwater encroachment is a hugely significant issue," the report noted, putting the words "hugely significant" in italics. It pointed out changing fresh water into salt water "can adversely affect the long-term term sustainability of Florida's water resources."

How does this happen? Florida's freshwater aquifer is not the only liquid roaring through the ground. It floats atop the remnants of an ancient sea that's trying to push its way upward. Until recently, that salty sea was held in check by the massive lens of fresh water above it, Arthur said.

"We're seeing the early stages of a shrinking of the freshwater lens of water in the aquifer," he said.

If Florida's freshwater bubble continues to shrink, "we'd have saltwater intrusion under the whole state. That's a nightmare scenario," said Knight of the Florida Springs Institute. "The evidence is there that we're changing our aquifer."

The geologists made a number of recommendations. They called for everything from increased monitoring statewide to figuring out how to change land use practices to cut back on the pollution. They sent their report to a host of state agencies.

However, Arthur said, "I am not aware of any formal action on the recommendations." The report "did raise eyebrows of some water managers in terms of importance," he said, but "there was a great desire to see what does the rest of this decade look like."

So his staff began work on a sequel, looking at data from 2003 to now. So far, he said, "the preliminary results indicate that the patterns are continuing."

However, as the springs' woes worsen, work on the second report is moving slowly.

"It is unfunded pretty much at this point," Arthur explained.

Before Disney and the beaches became major draws, springs were the state's biggest tourist attraction. They still lure plenty of visitors — thanks to taxpayers.

Beginning in 1949, the state has acquired 17 springs for its state park system. A 2003 study by Florida State found that four of the largest ones — Wakulla, Ichetucknee, Homosassa and Volusia Blue — each brought in $70 million annually, and each created 259 jobs. The impact "was similar to what spring training does, but all year long," said study co-author Mark Bonn.

So if those springs dry up, it's not just an environmental crisis — it's an economic catastrophe. Look what happened to the town of White Springs, north of Lake City.

In the early 1900s, so many wealthy tourists flooded White Springs seeking a medical cure from its waters that 13 hotels and a railroad line catered to them. Among the visitors: presidents Teddy Roosevelt and William Howard Taft.

The owner of the mineral spring built a four-story "spring house" around it to give patients access for their treatments for rheumatism, indigestion, dandruff and insomnia. The spring house still stands, but visitors are rare. The last hotel closed this year and the spring itself is a glorified mudhole.

"It started flowing less and would quit," said Dennis Price, a freelance geologist who lives in White Springs. "Then it would flow for a while and quit. People got so used to it that it became the norm. So when it quit for good, it wasn't the tragedy it should've been. We assumed it was part of the natural order, but it wasn't natural."

Pumping from a nearby phosphate mine drained so much water from the aquifer that the spring stopped its regular flow in the 1970s. Since then, whenever enough rain cascaded down into sinkholes and other fissures, the spring perked back up again — during flooding in 1998, it rose 35 feet and topped the railing around the top floor of the spring house — only to die back down afterward. There has been little flow since 1999.

But residents of White Springs are convinced their spring can be reborn. The phosphate mine has cut its water use. Mayor Helen Mills is trying to convince the state to clamp down on the other people slurping water from the aquifer, particularly businesses in Jacksonville she contends could get their water from the ocean or the St. Johns River.

"It's taken eons for the Florida aquifer to be formed," Mills said. "What they're doing is causing irreparable damage. ... We're a harbinger for what's going to happen to the rest of Central Florida."

Where water still emerges from springs, in many places it's now murky, plagued with nitrate pollution.

The nitrates, studies have shown for the past 20 years, come mostly from excess fertilizer, cattle feces and leaky septic tanks. It washes into the springs every time it rains. In Fanning Springs, in a state park in Levy County, the nitrate level is 100 times what it's supposed to be.

"Springs occur in areas where the aquifer is close to the surface, which means it's susceptible to contamination," explained Mark Stewart, a geology professor at the University of South Florida.

Polk of Western Kentucky University said he tested for nitrate pollution in every spring and sinkhole he investigated and "pretty much all of them had high levels."

The nitrates spur algae growth. The blooms started with a few wisps here and there 20 years ago, and now it's so thick it covers the sandy bottom at Silver Springs and coats the bright green eel grass in Rainbow Springs with a thick, brown fuzz. In Fanning Springs there's so much algae that virtually no other vegetation survives.

This is not just a cosmetic problem. The algae, a species called Lyngbya wollei, can be toxic to humans. In 2002 state officials began keeping a running tally of all the swimmers, kayakers, anglers and tubers who brushed up against it in state parks and then complained of suffering from rashes, hives, nausea, itching and asthma attacks. That overall tally has passed 140 reported incidents.

Florida officials began worrying about the dismaying trends in the early 1990s. Jim Stevenson, a state Department of Environmental Protection biologist as well as a cave diver, wondered why clear-as-glass Wakulla Springs near Tallahassee — famous for its glass-bottom boat tours — sometimes filled with murky water.

At one time, he said, "it was one of the best places in Florida to see birds and wildlife." But now, "they rarely ever have a day when they could give a glass-bottom boat tour anymore."

So Stevenson convened a group to try to figure out what was happening, and soon he had convened a second one to investigate changes at Ichetucknee Springs, a popular place for tubing.

Five months after being sworn in as governor in 1999, Bush took a canoe trip down the spring-fed Ichetucknee River with newly appointed DEP director David Struhs. Their guide: Stevenson.

"I don't know that either of them had ever seen a spring before," Stevenson said. "I just explained to (Bush) what was happening to the spring. The timing was good. They wanted to do something environmentally significant – and they did."

Bush and Struhs launched the Florida Springs Initiative and put it in Stevenson's hands. He pulled together experts from government, academia and industry. They recommended more than 100 ways to protect the springs, covering everything from legislation to land-use changes.

Bush made sure they had money to do the job, too, Stevenson said.

"In 2000 he gave us $2.5 million a year for springs protection — the first time Florida had spent money on springs protection," Stevenson, now retired, recalled.

Over the next decade, the state spent nearly $25 million. Groups were set up to study the biggest springs and suggest solutions tailored to their history, location and resources.

There seemed to be some hope for Florida's springs. It didn't last.

The biggest achievement of the Bush initiative, Stevenson said, was the state bought land to protect a lot of the springsheds — the area around the springs where runoff flows into the aquifer through sinkholes and other openings. That kept it from being paved over or converted to some polluting use.

The rest of the recommendations failed to get much traction in the Legislature.

A 2008 legislative report noted that "very few regulatory measures protecting springs have been adopted, yet several studies have indicated that nutrient pollution in spring discharge continues to rise."

That year, the DEP concluded the limit on nitrates in springs should be 0.35 milligrams per liter of water. Of the approximately 50 springs the agency was monitoring, three-fourths exceeded that level.

"The question is, will we be able to do something before the springs are all so polluted it won't matter any more," said former Republican state senator Burt Saunders of Naples, who sponsored a 2008 springs protection bill that failed. "In our current environment, it's unlikely."

The one measure the Legislature did pass came in 2010 — an effort to clean up leaking septic tanks. There are about 2.6 million septic tanks in the state, half of them more than 30 years old.

"People don't know what happens underground," said Lee Constantine, who as a Republican state senator from Altamonte Springs sponsored the septic tank bill. "It's an impending disaster."

After septic tank owners objected to the $150 inspections, though, legislators repealed the law this spring. Leading the effort to overturn it: incoming Senate President Don Gaetz, who originally voted for the inspections.

"By protecting these people from cleaning up their own mess, they are going to cost all of us a lot more," Constantine warned. "We are destroying Florida's heritage and passing on problems to our children for our own bottom line."

At the start of Scott's administration, the springs initiative was disbanded. That doomed the groups working on plans to heal individual springs. In June 2011, DEP officials told the groups to shut down.

"Due to reductions in the state budget brought on by hard economic times, Springs Initiative funding was not allocated by the legislature for fiscal year 2011/2012," the DEP letter said.

Since September, the Times has repeatedly asked to interview Scott and DEP Secretary Herschel Vinyard Jr. about how they are dealing with the springs, to no avail.

However, in May, Vinyard visited the Times editorial board to talk about a variety of issues. When asked what his department was doing about saving the springs, the only initiative he named was moving the Florida Geological Survey from one part of DEP to another.

This week, in response to repeated Times' questions, Vinyard's agency released a statement promising to ask legislators for $3 million next year for "springs-specific restoration projects."

Water issues are largely the purview of the state's five water management districts, which are in charge of issuing pumping permits and seldom reject one. Those decisions tend to be based on the impact of a single user and not on the cumulative impact of pulling so much water out of the ground, say former water district employees.

In May 2011, Mills, the White Springs mayor, and other officials and activists from the Suwannee River region urged the St. Johns River Water Management District to reject a permit that would allow the Jacksonville Electric Authority to take 163 million gallons out of the aquifer every day by 2031, up from the current 118 million gallons per day.

The Suwannee River Water Management District's then-executive director, David Still, opposed the permit too. Like Mills, he blamed the utility for taking away a lot of the spring flow: "It's JEA pumping the hell out of the aquifer.''

But he said top DEP officials muzzled him from speaking out at the final hearing, and the utility got its permit. He was subsequently pushed out of his job by the Scott administration as part of a massive shakeup and budget cutback of all five districts.

Before that happened, though, Still persuaded his cohorts at the St. Johns water district to ask scientists from the National Research Council for an impartial, nonpolitical study of what was happening to the aquifer and springs.

But after the council agreed to do the $400,000 study, the two water districts "were not able to come up with the funds," said Jeff Jacobs of the council.

Still scoffs at that. "They can fund what they want to fund," he said. "There just wasn't the will to do it."

The reason: If groundwater pumping is to blame, then the water districts will have to find other, more expensive sources of water, such as desalination.

But when springs disappeared in the past, Still pointed out, overpumping was named as the culprit.

Like many of Florida's springs, Kissengen Spring in Polk County was once a gathering place for a community, a place for swimming and socializing. In 1930, it gushed out 30 million gallons of water a day. Twenty years later, it dried up completely.

Investigations determined that it disappeared because its water was being sucked up by Polk's phosphate mines. Over the succeeding decades, the phosphate industry found ways to cut back its water use, but Kissengen didn't come back.

In 2002, not long after the start of Bush's initiative, state officials wondered if there was a way to revive Kissengen. Ron Basso of the Southwest Florida Water Management District, commonly called Swiftmud, studied the moribund spring and concluded it could happen. But the only way would be to reduce agricultural and residential water use — which had grown since the 1970s to absorb what the phosphate industry cut back — by 60 percent.

"That's just to get you back to just a trickle," Basso said.

After hearing his report, Swiftmud officials dropped the idea of reviving Kissengen.

More recently, though, staffers at two water agencies have contended that pumping is not affecting the springs as much as everyone thought.

In a September report, St. Johns River scientists contended that the key to Silver Springs' loss of flow was a lack of rainfall and excess vegetation, not the 2,500 permits authorizing the collective removal of 363 million gallons of water per day from the aquifer.

Then, in October, a Swiftmud scientist said computer modeling showed drought and sea level rise were the primary cause of a loss of flow in the Chassahowitzka spring and river region.

The St. Johns and Swiftmud findings run counter to a 2011 study by the U.S. Geological Survey of the spring-fed Ichetucknee's flow which blamed pumping, some of it from far away.

The river's lowest flows during most recent drought periods were lower than during droughts of the 1950s, even though there was more rainfall during the more recent drought. A similar pattern held true during high rainfall periods — the flow was lower than in the 1950s. That and other evidence pointed to pumping from as far away as Jacksonville that dropped the aquifer by as much as 90 feet in some places.

As an engineer specializing in hydrology who had worked at the Suwannee district since 1995, Still is among those skeptical that anything but pumping is to blame for the springs' lost water.

"These agencies are relying more on models than on the fact that you don't have an unlimited amount of water in the aquifer," he said. The problem, he contended, is politics: "If you've got a governor in place who hates water management, why should we protect springs?"

Earlier this year, a group of environmental advocates led by Estus Whitfield — who was a gubernatorial aide to Democrats Reubin Askew and Bob Graham, as well as Republicans Bob Martinez and Jeb Bush — rounded up 15,000 signatures on a petition demanding the state do more to protect Silver, Rainbow and other popular springs.

They took the petition to Tallahassee to hand it to Scott, but had to settle for Vinyard.

But before they could hand over the petition, Whitfield said, Vinyard handed them something of his own -- a three-page letter that contended the DEP was doing more for springs than ever before, devoting $11 million to "restoration, outreach, monitoring and research in our springs."

However, the head of DEP's division of environmental assessment and restoration, Drew Bartlett, said in a recent interview that about $8 million of that went for a statewide pollution monitoring system — not for restoration, outreach or research.

Of the rest, $900,000 is aimed at providing "better fertilizer technology" to farmers in North Florida, $300,000 is for eliminating a sewer discharge near Silver Springs and $1.1 million is supposed to eliminate a sewage spray field now polluting Kings Bay in Citrus County. Another $700,000 has not been earmarked, a DEP spokesman said.

Knight contended most of what was listed were "pork barrel projects that pay farmers and public utilities to do things they should be required to do with their own money."

He was skeptical of any real improvement, noting that the Silver Spring project merely moved a sewage sprayfield from one part of the springshed to another "with no public documentation of any water quality benefit."

The Vinyard letter boasted of making "meaningful progress" over the previous 18 months. However, when Bartlett was asked to name which springs were showing progress as a result of recent DEP efforts, the two he named — Wekiva and Wakulla — turned out to be showing improvement thanks to efforts put forward by the Bush-launched initiative.

The Vinyard letter also said the agency is now setting "nutrient reduction requirements" for Silver, Wakulla, Rainbow, Jackson Blue and Weeki Wachee. Whitfield was unimpressed because the requirements appear to call for no immediate action and nothing but voluntary reductions.

"Their contention is they're doing great," Whitfield said. But from what he could see, all DEP wanted to do was study the problem some more.

"Study, study, study, study — but at what point does it trigger an enforcement action?" he asked.

So far, Whitfield said, that three-page letter is "the only response we've ever gotten from anybody in the administration."

To Still, that's no surprise. Florida's officials won't try to fix the springs because Floridians regard their water supply as abundant and cheap, when the fact is it's neither. Until that attitude changes, he said, the springs will not be rescued.

"We don't care," he said. "We say we care. We give it lip service. But we don't care. The laws have allowed the degradation of those springs, and I don't think we as a society are going to get it changed."

Times staff researcher Caryn Baird contributed to this report. Craig Pittman can be reached at craig@tampabay.com.